1. Field of the Invention
The present invention relates to a ferrite core structure for surface-mounted device (SMD) especially to a new one which comprises of a ferrite core having gaps at both ends thereof and a conducting bracket and is manufactured by a new method applying transfer molding technology and punching technology.
2. Description of the Prior Art
Commonly used ferrite cores and manufacturing methods therefor are illustrated in FIG. 1 (A). In the figure, Ag-Pd alloy is electroplated at the bottom surface 811 of the ferrite core to form two electrodes 812, and the two ends 821 of the coil 82 wound on the ferrite core 81 are soldered to be fastened. The main disadvantages of the above-mentioned art are that Ag and Pd are expensive; electroplating waste water purification is so difficult that the cost is too high and ecology may suffer from serious damage if the waste water is not purified well.
Another prior art of a ferrite core structure 9 for SMD is to wind a coil 92 on the shaped ferrite core 91, and then to glue the ferrite core 91 to a base 93 having conductive electrodes 931 with glue, as shown in FIG.1(B) and FIG.1(C). The ferrite core manufactured in the above-mentioned process can keep Ag and Pd off, however, increasing base makes the process more complicated, and increases the volume and height such that manufacturing cost is not easy to be controlled.
According to the disadvantages of the prior arts described above, the inventor of the present invention ever proposed an improved art (please refer to Taiwan Patent No.458351, as shown in FIG.1 (D)), which effectively improves the disadvantages of prior arts, such as promoting mass production, lowering cost, circumstance protection, etc. However, the ferrite core of the art is essential to be adhered vertically to set such that it is not easy to be applied to light, thin and small-size electrical products due to the difficult of having suitable space. Thus the art still has an obvious disadvantage.
Besides, related prior arts can be referred to in JP Patent No.5-198438, which has the manufacturing process and composition similar to characteristics of the ferrite core for SMD. However, the disadvantages and defects of the art are described as follows:
1. Complicated manufacturing process- The ferrite core has to be manufactured during complicated sintering process and several times of lathing work. Besides, the lathed ferrite core has different roundness, which may cause changes in characteristic such that the quality can not be perfectly controlled.
2. Difficulty of Mass manufacture- The quality has to be kept according to manual work because of the complicated process. Therefore, continuous mass manufacture can""t be performed.
3. Molding problems- The ferrite core is molded after manufactured and thus the electric characteristic of the part is reduced.
4. The restrict of volume- Because the volume of the part can""t be reduced, there are some scruples and restrictions in applications.
5. High cost- Because the process is complicated and mass production is difficult, the manufacture cost is increased heavily.
Therefore, the commonly used structure and related process still have many disadvantages and really are not perfect designs such that improvement is required.
The inventor of the present invention ruminated over the disadvantages resulted from the commonly used ferrite core structures for SMD and manufacturing methods therefor, and earnestly deliberated the way of improvement and innovation. After studying hard for a long period, the inventor eventually succeeded in inventing the present invention, a new ferrite core for SMD and manufacturing method therefor.
The first purpose of the present invention is to provide a ferrite core structure for SMD, wherein two conductive terminals are revealed, and bended to parallel to the surface of the two insulating seats at both end portions symmetrically. In this way, the ferrite core structure can be placed horizontally relative to other parts to use such that the configuration of space can be more flexible.
The second purpose of the present invention is to provide a ferrite core structure for SMD and manufacturing method therefor, whereof the process of the present invention is simplified and manufacturing steps are reduced such that mass production is easier.
The third purpose of the present invention is to provide a ferrite core structure for SMD and manufacturing method therefor, wherein a ferrite core having gaps at both ends and a conducting bracket are used, and transfer molding technology and punching technology are used to manufacture the present invention such that electroplating process is avoided to protect the circumstance.
The ferrite core structure for SMD and manufacturing method therefor which can achieve the above-mentioned purposes is manufactured in following way. First, the conductive pieces extending from the conducting bracket are inset into the ferrite core column in advance. Then the transfer molding technology is utilized to form insulating seats at both ends of the ferrite core column. Finally, a coil-wound type inductor element is completed after the coil are wound on the portion of ferrite core without being enclosed by the insulating seat, and two ends thereof are soldered. According to the process of the ferrite core provided from the present invention can not only simplify the complicated process and manufacturing steps in commonly used arts but also promote mass production. Besides, the configuration of the space can be more flexible when the present invention is applied.